Hi Peter, it does sound great at first but it is tough to have the right cable always on hand.
We have some strict company rules, one of these is the color coding and marking of all junction boxes.
As an example all 277 lighting J box covers will be yellow, 120 lighting green.
A J box cover with 277 emergency lighting inside will be 1/2 orange 1/2 yellow.
We have a list of about 7 colors we use to identify deferent voltages and systems.
We also use a sharpie to write the panel and circuit on the cover.
Bob
